This invention is related to a Computer System having more than one Computer. This invention, especially, is related to the management method for Storage Subsystem in the Computer System wherein said Storage Subsystem is shared by more than one Computers.
The Computer System with which more than one user perform their business using more than one Client Computer is called a Client Computer System. Up to now, a Client Computer System is constructed with the Computers such as Personal Computers (PCs) in which all computational processings can be individually executed. The Computer which is used in such a Client Computer System is a kind of universal machine equipped with a highly efficient CPU, a large-capacity memory, large-capacity hard disk device and a high-speed graphic function, etc. and is therefore called by a popular name “Fat Client”. The Client Computer System composed of the Fat Clients is also called Fat Client System (FCS). In FCS, more than one Fat Client are mutually connected via LAN (Local Area Network), and communicate (transfer files, for example) each other depending on their requirements. The Fat Client is generally equipped with local disk units to store Operating System (OS), application programs or user data and so on. The OS and/or application programs are usually installed by user himself. The user data stored in their Client disk units is duplicated as backup data to a backup device such as the tape device installed in somewhere in the LAN so as not to be lost owing to an unexpected fault of the disk unit.
An another popular example of the Client Computer System is the Network Computer System. A Computer which composes Network Computer System is called an Network Computer (NC). As an NC, Computer with low price and low function and without disk units to store OS or application programs is used. Such a Computer is called “Thin Client” as compared with the Fat Client. The Client Computer System having the Thin Clients is called Thin Client System (TCS). In the TCS, for example, in more than one NC are connected to a server which is equipped with the Storage Subsystem such as the hard disk device via a LAN. The OS, application programs used by the NC system, and user data are stored in the Storage Subsystem linked with the server. The NC mounts the Storage Subsystem of the server as a remote Storage and makes use of the programs and data stored there. The OS which works on the NC, also, is loaded via a LAN from the Storage Subsystem of the server.